CVE-2026-56001

Name of the Vulnerable Software and Affected Versions libXfont2 versions prior to 2.0.8

Description A heap-based buffer overflow exists in the BitmapScaleBitmaps() function. The issue is caused by an integer overflow where a 32-bit size calculation wraps, resulting in an undersized heap allocation and subsequent out-of-bounds writes. An attacker with access to the X Server can trigger this by providing crafted font bitmap data, potentially leading to arbitrary code execution within the X server process and takeover of the display server context.

Recommendations Upgrade libXfont2 to version 2.0.8.